Bike 'Contrails' to Create DIY Bike Routes

Make Your Own Bicycle Path

Design21's Power to the Pedal design competition has a lot of interesting entries. One of the finalists that caught my eye is the Bike Contrails concept, though I'm not quite sure what to think about it.

Contrail is a tool for developing bicyle communities. As you ride, contrail leaves a fanit chalk line behind your bike. The goal is to encourge a new cycle of biking participation by allowing the biking community to leave a unique mark on the road and to reclaim this crucial shared space.

The old cycle: More cars on the road --> more percieved danger for bikers --> fewer bikers on road --> even more cars on the road.

The new cycle: A few bicyclists ride with contrail a couple times per week --> faint lines on the road inspire curiosity and remind bikers where it's safe to ride --> new bikers are encouraged to ride and use contrail --> contrail lines get brighter as community grows.

The device itself, pictured above, would basically be a small chalk-powder container. "A small amount of powdered chalk is filtered through a brush inside the device and picked up on a felt wheel. The felt wheel transfers this chalk onto the rear tire leaving a fine layer. As chalk builds up, the tire leaves a faint line of color on the roadbed. This is you contrail." This would allow cyclists to more easily know where to ride, and if enough cyclists ride always on the same place, it would create a visible bike path for motorists to avoid.

This is certainly an interesting concept, but I can't help but wonder how dangerous it could potentially be. Would that chalk on the tire reduce traction? How would that impact braking distances? How would the chalk interact with water, would it become even more slippery? Would those lines create confusion among motorists?